Sources
Hot Wheels are available in most toy and department stores, though some models are only sold by specific retailers and others have low production runs. Collectors can find rare and older models through online auction sites and dealers, as well as at toy shows and Hot Wheels conventions.
Grading
Collectors and dealers assign grades to indicate a car's condition which range from mint, reserved for a flawless car, to beater, indicating a car with multiple serious defects. Physical defects that affect a car's value include paint chips or scratches, dents, cracked windshields and missing tires.
Redlines
Redlines are Hot Wheels cars produced between 1968 and 1972, which all had red lines painted along each tire's circumference. Redlines are prized by collectors and occasionally counterfeited by unethical dealers who alter Hot Wheels to replicate genuine redlines.